I have seen a nice post on LinkedIn about how to become a CISSP in 30 days. I think it is a very aggressive schedule but if you can spare 40+ hours over the next 30 days, it MIGHT be doable. If you can't dedicate that much time or more, then it may not be the best recipe for you and you may have to stretch your learning time a bit. See article extract below:

Like many of my InfoSec brethren, I am bored to tears with news of the “IT security skills gap.” There are far too many intelligent and hardworking people left on the sidelines because they don’t have the exact right mix of certifications, education, and experience for us to be talking about a skills gap. But I’m not one to complain. Like it or not, InfoSec hiring managers, recruiters, and HR professionals love certifications. So I’m going to show you how to get them!

This study guide is the first in a series of guides I plan to write about how to prepare for information security exams. I’m starting with the Certified Information Systems Security Professional (CISSP) study guide since it is the most recognized Information security exam.

This exam prep guide consists of four phases: plan, review, practice, test. In the following sections, I’ll provide a brief overview of what’s done in each phase. This guide is aimed primarily at experienced IT professionals. Many of you will easily be able to complete this certification in 30 days (or less) by following this plan.

I have asked this question on the ISC2 community website. See the response I have received within this article. I have reformatted the article for the look but it is the verbatim response that I have received from ISC2.

From the ISC2 website: Beginning in April 2018, the CISSP® exam will be based on a new exam outline. In advance of the new exam outline being available, the Detailed Content Outline (DCO) is currently available. The DCO is a less detailed version of the exam outline but will give you an overview.